[Intel-gfx] [PATCH v3 04/11] drm/i915: LVDS pixel clock check

Mika Kahola mika.kahola at intel.com
Fri Jul 31 05:13:53 PDT 2015


It is possible the we request to have a mode that has
higher pixel clock than our HW can support. This patch
checks if requested pixel clock is lower than the one
supported by the HW. The requested mode is discarded
if we cannot support the requested pixel clock.

This patch applies to LVDS.

V2:
- removed computation for max pixel clock

V3:
- cleanup by removing unnecessary lines

Signed-off-by: Mika Kahola <mika.kahola at intel.com>
---
 drivers/gpu/drm/i915/intel_lvds.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index cb634f4..59213f9 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -289,11 +289,14 @@ intel_lvds_mode_valid(struct drm_connector *connector,
 {
 	struct intel_connector *intel_connector = to_intel_connector(connector);
 	struct drm_display_mode *fixed_mode = intel_connector->panel.fixed_mode;
+	int max_pixclk = to_i915(connector->dev)->max_dotclk;
 
 	if (mode->hdisplay > fixed_mode->hdisplay)
 		return MODE_PANEL;
 	if (mode->vdisplay > fixed_mode->vdisplay)
 		return MODE_PANEL;
+	if (mode->clock > max_pixclk)
+		return MODE_CLOCK_HIGH;
 
 	return MODE_OK;
 }
-- 
1.9.1



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